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| //===--- ShrinkToFitCheck.cpp - clang-tidy---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ShrinkToFitCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
#include "llvm/ADT/StringRef.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace modernize {
void ShrinkToFitCheck::registerMatchers(MatchFinder *Finder) {
if (!getLangOpts().CPlusPlus11)
return;
// Swap as a function need not to be considered, because rvalue can not
// be bound to a non-const reference.
const auto ShrinkableAsMember =
memberExpr(member(valueDecl().bind("ContainerDecl")));
const auto ShrinkableAsDecl =
declRefExpr(hasDeclaration(valueDecl().bind("ContainerDecl")));
const auto CopyCtorCall = cxxConstructExpr(hasArgument(
0, anyOf(ShrinkableAsMember, ShrinkableAsDecl,
unaryOperator(has(ignoringParenImpCasts(ShrinkableAsMember))),
unaryOperator(has(ignoringParenImpCasts(ShrinkableAsDecl))))));
const auto SwapParam =
expr(anyOf(memberExpr(member(equalsBoundNode("ContainerDecl"))),
declRefExpr(hasDeclaration(equalsBoundNode("ContainerDecl"))),
unaryOperator(has(ignoringParenImpCasts(
memberExpr(member(equalsBoundNode("ContainerDecl")))))),
unaryOperator(has(ignoringParenImpCasts(declRefExpr(
hasDeclaration(equalsBoundNode("ContainerDecl"))))))));
Finder->addMatcher(
cxxMemberCallExpr(
on(hasType(hasCanonicalType(hasDeclaration(namedDecl(
hasAnyName("std::basic_string", "std::deque", "std::vector")))))),
callee(cxxMethodDecl(hasName("swap"))),
has(ignoringParenImpCasts(memberExpr(hasDescendant(CopyCtorCall)))),
hasArgument(0, SwapParam.bind("ContainerToShrink")),
unless(isInTemplateInstantiation()))
.bind("CopyAndSwapTrick"),
this);
}
void ShrinkToFitCheck::check(const MatchFinder::MatchResult &Result) {
const auto *MemberCall =
Result.Nodes.getNodeAs<CXXMemberCallExpr>("CopyAndSwapTrick");
const auto *Container = Result.Nodes.getNodeAs<Expr>("ContainerToShrink");
FixItHint Hint;
if (!MemberCall->getBeginLoc().isMacroID()) {
const LangOptions &Opts = getLangOpts();
std::string ReplacementText;
if (const auto *UnaryOp = llvm::dyn_cast<UnaryOperator>(Container)) {
ReplacementText =
Lexer::getSourceText(CharSourceRange::getTokenRange(
UnaryOp->getSubExpr()->getSourceRange()),
*Result.SourceManager, Opts);
ReplacementText += "->shrink_to_fit()";
} else {
ReplacementText = Lexer::getSourceText(
CharSourceRange::getTokenRange(Container->getSourceRange()),
*Result.SourceManager, Opts);
ReplacementText += ".shrink_to_fit()";
}
Hint = FixItHint::CreateReplacement(MemberCall->getSourceRange(),
ReplacementText);
}
diag(MemberCall->getBeginLoc(), "the shrink_to_fit method should be used "
"to reduce the capacity of a shrinkable "
"container")
<< Hint;
}
} // namespace modernize
} // namespace tidy
} // namespace clang
|